Starting with version 4.9, GCC assumes it can't safely dereference null pointers, and uses this for some optimizations. On s390, the lowcore memory is located at address 0, so this assumption is wrong and breaks the s390-ccw firmware. Pass -fdelete-null-pointer-checks to avoid that.
Cc: Cornelia Huck <cornelia.h...@de.ibm.com> Cc: Christian Borntraeger <borntrae...@de.ibm.com> Cc: Alexander Graf <ag...@suse.de> Signed-off-by: Aurelien Jarno <aurel...@aurel32.net> --- pc-bios/s390-ccw/Makefile | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/pc-bios/s390-ccw/Makefile b/pc-bios/s390-ccw/Makefile index 009bb8d..746603a 100644 --- a/pc-bios/s390-ccw/Makefile +++ b/pc-bios/s390-ccw/Makefile @@ -10,7 +10,7 @@ $(call set-vpath, $(SRC_PATH)/pc-bios/s390-ccw) .PHONY : all clean build-all OBJECTS = start.o main.o bootmap.o sclp-ascii.o virtio.o -CFLAGS += -fPIE -fno-stack-protector -ffreestanding +CFLAGS += -fPIE -fno-stack-protector -ffreestanding -fno-delete-null-pointer-checks LDFLAGS += -Wl,-pie -nostdlib build-all: s390-ccw.img -- 2.1.4
